The present invention relates to a quick clamping type vice including a vertically up and down movable chuck. A bottom of the chuck is formed with 180 degrees thread. The thread of the chuck can be vertically 180 degrees engaged with or disengaged from a thread rod so that the vice can be conveniently operated with less strength for tightly clamping a work piece or loosening the work piece. The vice is applicable to a carpenter or a cramp working bench or other working sites necessitating clamping of a work piece.
In wood work or bench work, in order to stabilize a work piece, a vice is often used to clamp the work piece. In a conventional vice, a thread rod is connected with a clamping block mounted on a working bench. In both clamping and loosening operation, it is necessary to rotate the thread rod many times. In U.S. patent application Ser. No. 08/905,388 of the present applicant, entitled "a working bench with quick clamping type cramp device", as shown in FIGS. 1 and 2, a quick clamping type vice is disclosed. The vice includes a main base seat 71, a back seat 72, a movable block 73 and a ratchet lever 75. The back seat 72 is spaced from and opposite to the main base seat 71. The movable block 73 is driven by a thread rod 74. The ratchet lever 75 is coupled with the thread rod 74 via an internal ratchet. A oneway release handle 76 formed with a thread is disposed on the main base seat 71 and engaged with the thread rod 74. When using the vice to clamp a work piece 50, the release handle 76 is pressed and shifted to separate the thread thereof from the thread rod 74. At this time, the movable block 73 can be quickly moved to attach to the work piece 50. Then the ratchet lever 75 is rotated several times to drive the movable block 73 to clamp the work piece 50. When releasing the work piece 50, as shown in FIG. 2-1, the pawl 751 is shifted to reversely engage the crank lever 75 with the internal ratchet. Then the crank lever 75 is rotated several times to move the movable block 73 away from the work piece 50. Thereafter, the release handle 76 is pressed to quickly slide the movable block 73 backward. Such structure is able to quickly fixedly clamp the work piece 50. However, the loosening operation of the work piece 50 is relatively troublesome. The thread of the release handle 76 is moved along an arch path so that the thread will slightly force the thread of the thread rod 74 and slightly move the movble block 73 forward. Therefore, when the movable block 73 suffers a pressure in a clamping state, it will be impossible to shift down the release handle 76 so that the movable block 73 cannot be quickly slided.